Human growth normally occurs, in simplified terms, as a result of growth hormone secretion by the pituitary gland. In less simplified terms, growth occurs as a result of a complex interplay of factors. Accordingly, when a child is observed to be of unusually short stature for his or her age and a growth hormone deficiency is suspected, it is the current practice to administer various drugs to the child in an effort to provoke secretion of growth hormone. Normally, at least two provocative tests are administered; if the peak growth hormone response is less than 10 ng/mL after each administration of provocative drugs, then a diagnosis of growth hormone deficiency is usually made.
However, growth hormone secretion occurs in pulsatile or episodic patterns, i.e., at any given time a measurement of growth hormone secretion is likely to be very low, even in individuals not suffering from growth hormone deficiency, because such a measurement is highly likely to be taken between pulses.
Those suffering from a growth hormone deficiency may be misdiagnosed if a reading of growth hormone secretion is taken during a secretory pulse, i.e., the level of growth hormone may seem normal but such apparent normality may be attributable merely to the fact that growth hormone secretion was checked at its peak. Where growth hormone secretion is being checked after the administration of a provocative drug, it is important for the physician to know what amount of secretion is a result of the provocation, and what amount would have been secreted even in the absence of provocation.
The physician has no means for determining whether or not a particular patient is undergoing a secretory pulse at the time a reading is made. Just as importantly, a pulse may be beginning or ending when the reading is made, thereby producing skewed results that can lead to a misdiagnosis.
The art has dealt with this problem by taking multiple tests, in the hope that the physician will be able to make a meaningful interpretation of the test results if there is a large body of data to interpret.
The present technique is subject to many pitfalls and there is a need for a more reliable diagnostic method. However, the prior art, taken as a whole, neither teaches nor suggests how the present procedure could be improved.